<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
<style>
    div{
        display: inline;
        background-color: lightgoldenrodyellow;
        width: 200px;
        height: 200px;
        border: 1px solid lawngreen;
    }
    span{
        display: block;
        background-color: lightgoldenrodyellow;
        width: 200px;
        height: 200px;
        border: 1px solid lawngreen;
    }
</style>
</head>
<body>
<!--行内元素 和 块级元素没有太明显的界限
可以通过display属性,将二者进行转换-->
<div>
    AAAA
</div>
<div>
    BBBB
</div>
<hr>
<span>VVVV</span>
<span>FFFF</span>



</body>
</html>